On routine testing, it was discovered that two patients with malignant melanoma had developed the red blood cell antibody, anti-Chido (Cha), following the initiation of cancer immunotherapy in the treatment of their disease. We are currently testing the Cha antigen status of the remaining persons in this protocol to see if the number varies from the statistical norms of 98% Cha positive. We are attempting to test the Cha antigen status of three cell lines of neuraminidase treated and untreated cultured melanoma cells used for injection in this protocol to determine if these cells can be responsible for inducing antibody production.